1/11While some may think 802 ci of fuel-injected mountain motor might be overkill for the street, they haven't felt power like this flowing through their veins. Even more amazing is that this thing runs on 89-octane pump gas. Inexpensive it is not, however.

In the ever-escalating war of large-displacement engines, Sonny Leonard is one of the field generals. Sonny's Automotive Racing is well known for building big-power, huge-displacement racing engines, but it's just as adept at streetable pump gas combinations. A really big pump gas engine is what popped into Dave Traitel's mind when he thought about the kind of car he'd like his company, TKO MotorSports, to build for fellow extreme car enthusiasts, so he called Leonard to bench race.

"I chose Sonny because of an article I had read about one of his engines," Traitel explains. "I was really taken by the amount of power this motor was making. Yet, while I like horsepower, I also like torque. I remembered from my ranching days that torque is a great friend because of the amount of pulling required in the field. So they got back to me with this 802 pump gas combination," he continues. "Something that was user-friendly was a big selling point for me. I wanted to spend less time working on it and more time enjoying it--and I was amazed at how easily it idled and the power it made."

When we heard the engine was going together, we followed along to see what goes into such an enormous engine and how it's possible to tame it for the street. Sonny's used its vast experience in mountain motor technology to produce a short-block assembly that was up to the rigors of street driving as well as an occasional dragstrip blast. Big cubic inches like this aren't possible with a standard big-block Chevy deck height or 4.840-inch bore spacing, so an aftermarket Donovan billet aluminum block with 5.000-inch bore spacing was used as a starting point. Stepped iron sleeves that were honed down to a final bore size of just about 4.75 inches provided just the right combination of bore to go with the 5.700 stroke.

2/11Really big cubic inches are starting to become en vogue for the street. Placing the Donovan 5.000-inch-bore space aluminum block beside a standard 500-cubic-inch NHRA Pro Stock block offers an idea of just how big these engines are.

With a Sonny Leonard billet crank and gas-ported Bill Miller pistons, about the only difference between this and what's found in an IHRA Pro Stock engine are the connecting rods and compression ratio. Sonny's used steel rather than aluminum rods for the sake of durability and a pump-gas-able 11.0:1 compression ratio to help minimize the possibility of detonation with 89-octane.

The most powerful head combination available for this block was Sonny's Next Generation GM hemispherical head. With its unique combustion chamber, revised valve location, and relocated spark plugs, this is the exact same head that's made the 6.20-second IHRA Pro Stock cars the quickest naturally aspirated quarter-mile race cars on the planet today. To make a beast like this more driveable on the street, Sonny used a sheetmetal intake with shorter runners to help harness some of the torque. He also utilized a different cam grind with a bit less intake duration than normal for the same purpose.

Driveability is further enhanced by a BigStuff3 engine management system. Designed by engine management guru John Meaney, this system was originally tested and developed on Meaney's own 1,000-plus-horsepower Corvette that is regularly driven. Utilizing a sequential system like the BigStuff3 makes even more sense with an engine of this size, as fuel delivery can be tailored to each individual cylinder, which helps greatly in optimizing the overall power potential. With dual wideband O2 sensors and onboard data acquisition, the resulting idle quality is very smooth--even with big 96 lb/hr injectors.

Of course, fuel management is just one part of the equation for making horsepower. You have to have airflow--and plenty of it--to make power. Sonny's utilized its own billet throttle bodies with oversized 2.500-inch throttle bores to allow the maximum amount of airflow into this hungry monster. Mountain motor Pro Stock technology was again incorporated into this design with the utilization of four different two-barrel throttle bodies rather than dual four-barrels. Separating them allows for optimal spacing directly over the intake runners for better distribution and velocity.

3/11There's a lot of metal turning around inside the crankcase of a monster motor, which is why only the finest aftermarket pieces can be used. The crankshaft, shown here on the balancing machine, is a Sonny Leonard billet steel crank with a monster 5.700-inch stroke.

While making big numbers with 89-octane might have seemed like a stretch, the dyno showed this combination was right there with 1,417 peak horsepower at 7,100 rpm and 1,140 lb-ft at 5,800. Of course, Traitel's vision of having one of the quickest street cars on the planet didn't stop there. Sonny's added a Speedtech single-stage wet fogger, which can produce another 300 hp for whenever the car ventures onto the dragstrip.

Traitel did his part by adding a professionally built double-framerail chassis for his fiberglass-bodied '41 Willys coupe, which is certified to run into the low-6-second range. Backing that up will be all the necessary safety equipment, so the car will always be a welcome visitor at any sanctioned dragstrip. The end result is going to be a street/strip cruiser that's at the top of the food chain wherever it goes. With Traitel already having plans in the works for a similarly powered '63 split-window street Vette, this may be the beginning of a trend, as pump gas monster engines make the jump from strip to street. In fact, Sonny's has already delivered a pair of carbureted 762ci pump gas engines along with a 520-plus-cubic-inch small-block, so big is en vogue.

11/11

Sonny's shook the industry in late 2007 when it introduced the aftermarket's first 5.300 bore-center engine that allows displacements once considered near impossible. At the '08 PRI show, Sonny unveiled an 892ci monster motor (right, dwarfing a standard 4.840-inch bore-center big-block) aimed squarely at the ADRL Pro Stock, Pro Xtreme, Quick 16, and PSCA Pro Street marketplaces. Available with either hemispherical- or wedge-style heads, the 892 has already posted 2,072 naturally aspirated horsepower with 1,444 lb-ft, and several engines are already out in the field now undergoing testing and waiting for the '09 season to get into full swing.